Generally, the widely-used peripheral input device of a computer system includes for example a mouse device, a keyboard device, a trackball device, or the like. Via the keyboard device, characters or symbols can be inputted into the computer system directly. As a consequence, most users and most manufacturers of the input devices pay much attention to the keyboard devices.
Please refer to FIGS. 1, 2 and 3. FIG. 1 is a schematic top view illustrating the outward appearance of a conventional keyboard device. FIG. 2 is a schematic perspective view illustrating a portion of the conventional keyboard device of FIG. 1. FIG. 3 is a schematic exploded view illustrating a portion of the conventional keyboard device of FIG. 1. For succinctness, only a portion of the key frame, a single key structure and associated components are shown in FIGS. 2 and 3.
The conventional keyboard device 1 comprises plural key structures 10, a base plate 11, a membrane circuit board 12 and a key frame 13. The membrane circuit board 12 comprises plural membrane switches 121 corresponding to the plural key structures 10. Each of the plural key structures 10 comprises a keycap 101, a scissors-type connecting element 102 and an elastic element 103. The scissors-type connecting element 102 is connected between the keycap 101 and the base plate 11. Moreover, the scissors-type connecting element 102 comprises a first frame 1021 and a second frame 1022. The second frame 1022 is pivotally coupled to the first frame 1021. Consequently, the first frame 1021 and the second frame 1022 can be swung relative to each other. The elastic element 103 is arranged between the keycap 101 and the base plate 11. Moreover, the elastic element 103 comprises a contacting part (not shown).
While the keycap 101 of any key structure 10 is depressed and moved downwardly relative to the base plate 11, the first frame 1021 and the second frame 1022 of the scissors-type connecting element 102 are switched from an open-scissors state to a stacked state. Moreover, as the keycap 101 is moved downwardly to compress the elastic element 103, the corresponding membrane switch 121 is pushed and triggered by the contacting part of the elastic element 103. Consequently, the keyboard device 1 generates a corresponding key signal. When the keycap 101 of the key structure 10 is no longer depressed, the keycap 101 is moved upwardly relative to the base plate 11 in response to an elastic force of the elastic element 103. Meanwhile, the first frame 1021 and the second frame 1022 are switched from the stacked state to the open-scissors state again, and the keycap 101 is returned to its original position.
Moreover, the key structures 10 of the keyboard device 1 are classified into some types, e.g., ordinary keys, numeric keys and function keys. When one of the key structures 10 is depressed by the user's finger, a corresponding key signal is generated to the computer, and thus the computer executes a function corresponding to the depressed key. For example, when an ordinary key is depressed, a corresponding letter is inputted into the computer. When a numeric key is depressed, a corresponding number is inputted into the computer. In addition, the function keys (F1˜F12) can be programmed to provide various quick access functions. For allowing the user to recognize the functions of all key structures 10, the keycaps of these key structures 10 are printed with the corresponding key symbols. For example, the key symbols include ordinary symbols 1011, numeric symbols 1012 and/or access function symbols 1013.
Generally, the arrangements of the key symbols for different languages are distinguished. In views of cost-effectiveness, the manufacturer prefers to sells the same kind of keyboard device 1 to different countries. However, if the arrangements of the key symbols to be printed on the keycaps 101 of the keyboard device 1 are changed according to the languages of different countries, the printing process is very complicated. Moreover, after the key symbols have been printed on the keycaps 101 of the keyboard device 1, the arrangement of the key symbols on the keycaps 101 cannot be changed. Since the arrangement of the key symbols on the keycaps 101 cannot be changed, the conventional keyboard device 1 is not user-friendly to the user that intends to change the arrangement of the key symbols. In other words, the conventional keyboard device 1 needs to be further improved.